A modulation method that needs to be used for a nonlinear channel has relatively small envelope fluctuation. To improve spectral bandwidth utilization, signal transmission generally uses a higher-order modulation method combining an amplitude and a phase. When a frequency of a carrier and a modulation order are relatively high, phase noise has relatively great impact on the modulation method.
For example, in the IEEE (Institute of Electrical and Electronics Engineers) 802.11ad communication protocol, an operating band of a carrier is 60 GHz (Gigahertz). An SC PHY (single carrier physical layer) and an OFDM PHY (orthogonal frequency division multiplexing physical layer) are defined in the IEEE 802.11ad communication protocol. Due to a relatively high PAPR (peak-to-average power ratio), the OFDM PHY has a high requirement on a power amplifier and is not industrialized. To lower the requirement on the power amplifier, the SC PHY supports only a modulation method of a maximum of 16QAM (quadrature amplitude modulation). If a modulation order is improved, phase noise may cause great interference, and after decoding, a bit error rate may fail to meet a data transmission requirement.
In the prior art, in order to suppress phase noise introduced in a transmission process, phase adjustment is further performed on a data symbol by using a pilot estimation phase noise control algorithm, for example, a linear PNC (phase noise cancellation) algorithm, to enhance a phase noise suppression capability of a modulated signal. However, in such a manner, a phase noise suppression capability is limited, and a higher-order modulation requirement cannot be met.